TSX-listed Ivanhoe Mines’ South African subsidiary Ivanplats and its partners have announced “outstanding” positive results of an independent feasibility study for the company’s tier-one Platreef palladium, rhodium, nickel, platinum, copper and gold project in South Africa.

The feasibility study provided the blueprint for the ongoing development of the Platreef project and builds on the results of a preliminary economic assessment (PEA) for a phased-development scenario to expedite production, which was announced in November 2020, alongside the 2020 feasibility study.

“These . . . results define our commitment to advance Platreef to first production, alongside our local communities and . . . partners. We are counting down to less than 30 months from now.

"This achievement will only mark the first milestone, as we plan to expand this world-scale operation into one of the largest and lowest-cost integrated platinum group metals (PGMs) producers on the planet, all while generating outstanding returns on capital for a major, disruptive mine,” said Ivanhoe co-chairperson Robert Friedland at the thirty-first BMO Global Metals & Mining Conference in Florida, in the US, on February 28.

The 2022 feasibility study for Platreef was based on a steady-state production rate of 5.2-million tonnes a year, as well as an accelerated ramp-up to steady state through the earlier development of Shaft 2. The study was based on the detailed design and engineering scenario first presented in the 2020 PEA, confirming the viability of a new phased development pathway to fast-track Platreef into production by the third quarter of 2024.

The new feasibility study’s first phase of production included an initial 700 000 t/y underground mine and a concentrator with a capacity of 770 000 t/y, targeting high-grade mining areas close to the project's recently completed Shaft 1.

Platreef's 5.2-million-tonne-a-year steady-state production rate following Phase 2 development would rank it as the world's fifth-largest primary PGMs mine on a palladium-equivalent basis, the company said, with yearly forecast production of more than 590 000 oz of palladium, platinum, rhodium and gold, plus more than 40-million pounds of nickel and copper.

The 2022 feasibility study reflected the initial two phases of development for the Platreef mine. Previous studies demonstrated the resource base for future expansions up to 12-million tonnes a year, which would position Platreef among the largest PGM-producing mines globally.

The Platreef project – which includes an underground deposit of thick, high-grade platinum group element (PGE)/nickel/copper/gold mineralisation discovered by Ivanhoe's geologists – is in the northern limb of the Bushveld Complex about 11 km from Mokopane and 280 km northeast of Johannesburg.

PGE/nickel/copper/gold mineralisation in the northern limb is primarily hosted within the Platreef, which is a mineralised sequence that is traced more than 30 km along strike. The Platreef project is situated in the southern sector of the Platreef on two contiguous properties – Turfspruit and Macalacaskop – which comprise about 7 842 ha.

The northernmost property, Turfspruit, is contiguous with and along strike from platinum miner Anglo American Platinum's Mogalakwena group of properties and mining operations.

Ivanplats acquired a prospecting permit for Macalacaskop and Turfspruit in February 1998. In 1999, Ivanhoe began a series of drilling campaigns, totalling more than 726 000 m, to advance Platreef from a greenfield exploration project focused on shallow mineralised zones through to focusing on deeper underground targets. At the height of the drilling campaign, 30 diamond drill rigs were producing more than 10 000 m of core a week.

Since 2007, Ivanplats has focused its Platreef exploration and development activities on defining and advancing the thick, high-grade, down-dip extension of its original discovery at Platreef, now known as the Flatreef deposit. In 2012, the Merensky Reef analogue was recognised.

The Flatreef deposit lies entirely on the Turfspruit and Macalacaskop properties that form part of Ivanhoe's mining right.

The thickness of the mineralised reef – T1 and T2 mineralised zones – intersected in Shaft 1 is 29 m, with an average grab sample grade of 6.35 g/t platinum, palladium and rhodium plus gold (3PE+Au), ranging up to 9.6 g/t 3PE+Au, as well as significant quantities of nickel and copper. For comparison, the typical reefs being mined elsewhere on South Africa's Bushveld Complex are about 1 m thick.

"The thick and flat-lying nature of the high-grade mineralisation of the Flatreef deposit allows for the use of state-of-the-art, automated, electric mining machinery, including cutting-edge battery-driven underground vehicles,” Friedland explained.

A consortium led by Japanese government entity Japan Oil, Gas and Metals National Corporation, including Japanese trading company Itochu and engineering company Japan Gas Corporation, acquired a 10% interest in the Platreef project for about $290-million.

In June 2020, Ivanplats completed the sinking of Platreef's initial shaft, Shaft 1, to its final depth of 996 m below surface. Shaft 1 is located about 450 m away from a high-grade area of the Flatreef orebody, which will provide initial mining areas for Phase 1 production in 2024.

The thick Flatreef orebody also is flat-lying, which the company said was ideal for safe, bulk-scale, mechanised mining and process-optimisation for maximum ore extraction.

"Palladium and rhodium have reached all-time highs in recent years, currently trading at [about] $2 480/oz and $18 750/oz respectively, as progressively stricter air-quality rules increase demand for the metals used in vehicle pollution-control devices.

"Meanwhile, copper and nickel will continue to realise historic and sustained rallies [owing] to underinvestment in new mine supply and massive growing demand tied to electric vehicles and global clean-energy initiatives," Friedland said.